I am new to firedrake, and also a linux amateur. I am using Ubuntu bash shell to install it via the commands you list, but am getting a variety of errors. 

In particular, on this last installation attempt, I keep getting lines that say "failed to clone (something) using ssh, falling back to https" then

"Permission denied (publickey).

fatal: Could not read from remote repository."

Can you help or point me to someone who can?

thanks

Eric Malitz